Simplify the following expression: $q = \dfrac{5z}{4} - \dfrac{3z}{4}$
Since the expressions have the same denominator we simply combine the numerators: $q = \dfrac{5z - (3z)}{4}$ Combine like terms: $q = \dfrac{2z}{4}$ Simplify by dividing numerator and denominator by 2: $q = \dfrac{z}{2}$